Battery

The battery charger is included (of course). But, I need to get another converter to have it works — when I plug it directly to power source. The good thing is that it has less items. On Nokia N8 for example, you will get charger and USB data cable. N9’s cable charger is also the USB cable data. Not sure whether N9 only have the white color for its charger, I got almost everything in black (USB cable/charger, earphone, phone body, and phone case) but not the power charger.
Nokia N9 claims to have a good battery life. Here’s the battery features according to Nokia N9 specifications page:

• Talk-time (maximum): GSM 11 hours / WCDMA (3G) 6.5 hours
• Standby time (maximum): GSM 340 hours / WCDMA (3G) 420 hours
• Video playback time (720P) 5 hours
• Music playback time 50 hours
• Web browsing (maximum): WLAN 6.5 hours / HSDPA (3G) 5 hours

But, there are some factors to get that maximum performance. The signal strength for example, or probably multi-tasking (switching between multiple applications), brightness display, etc. Anyway, since the battery phone is planted inside the body, it’s not easy to replace the battery later (or, more importantly, can I change the battery when needed?). But, this is something that happened probably once in few years. I’ve been using Nokia N8 for more than a year, and battery is not an issue. I hope Nokia N9 has the same battery quality.
When I actively use this phone (without wireless connection), I need to recharge it after 4-5 hours. Again, the battery life for a full charging cycle my vary. Having it in Airplane mode and connect to wireless network should be much better. I do this when I’m at work.